US20060213891A1 - Arc welding system - Google Patents

Arc welding system Download PDF

Info

Publication number
US20060213891A1
US20060213891A1 US11/090,576 US9057605A US2006213891A1 US 20060213891 A1 US20060213891 A1 US 20060213891A1 US 9057605 A US9057605 A US 9057605A US 2006213891 A1 US2006213891 A1 US 2006213891A1
Authority
US
United States
Prior art keywords
defined
electric arc
dc
welding system
arc welding
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
US11/090,576
Other versions
US7968822B2 (en
Inventor
Elliott Stava
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lincoln Global Inc
Original Assignee
Lincoln Global Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lincoln Global Inc filed Critical Lincoln Global Inc
Priority to US11/090,576 priority Critical patent/US7968822B2/en
Assigned to LINCOLN GLOBAL, INC. reassignment LINCOLN GLOBAL, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: STAVA, ELLIOTT K.
Publication of US20060213891A1 publication Critical patent/US20060213891A1/en
Application granted granted Critical
Publication of US7968822B2 publication Critical patent/US7968822B2/en
Application status is Active legal-status Critical
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00Arc welding or cutting
    • B23K9/09Arrangements or circuits for arc welding with pulsed current or voltage
    • B23K9/091Arrangements or circuits for arc welding with pulsed current or voltage characterised by the circuits
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K9/00Arc welding or cutting
    • B23K9/095Monitoring or automatic control of welding parameters
    • B23K9/0956Monitoring or automatic control of welding parameters using sensing means, e.g. optical

Abstract

An electric arc welding system including a power lead for providing welding current between an advancing welding wire and a workpiece, a short circuit sensor having a short circuit output signal when the electrode is shorted with the workpiece and a premonition sensor having a fuse output signal when a short circuit is about to break. This welding system has at least two power source modules, each with a common isolated DC input and an output connected to the power lead with each of the modules controlled to perform a short circuit arc welding process. The individual module comprises a regulated DC to DC converter having a DC output signal with a waveform controlled by a waveform signal from a controller and an output switch receiving the DC output signal and in series with the power lead where the output switch is opened by a gate signal to reduce the welding current in the power lead.

Description

  • The present invention relates to the art of electric arc welding and more particularly to an arc welding system utilizing a plurality of power modules for driving a single welding operation.
  • INCORPORATION BY REFERENCE
  • In the electric arc welding industry, it is known to drive a single welding operation by a series of power source modules preferably connected in parallel, but sometimes connected in series. The Lincoln Electric Company of Cleveland, Ohio is a pioneer in this technology and has several patents such as Stava U.S. Pat. No. 6,291,798; Stava U.S. Pat. No. 6,365,874; Houston U.S. Pat. No. 6,472,634; and, Myers U.S. Pat. No. 6,847,008. These patents are incorporated by reference herein to illustrate the general technology forming s background concept related to the present invention. The Lincoln Electric Company is also the pioneer of a welding process utilizing controlled arc and short circuit conditions in a single cycle wherein the short circuit condition is sensed by a detector and the arc condition is determined by a detector. This proprietary welding process is disclosed in several patents including Parks U.S. Pat. No. 4,717,807; Parks U.S. Pat. No. 5,003,154; Stava U.S. Pat. No. 5,148,001; Stava U.S. Pat. No. 6,160,241; and, Stava U.S. Pat. No. 6,501,049. These patents relating to s proprietary short circuit type welding process to which the present invention is particularly directed are incorporated by reference herein as further background information. All of these patents relate to certain concepts employed in the present invention and are incorporated into this application so that the technology is disclosed so there is no necessity for duplicating such background technology.
  • BACKGROUND OF INVENTION
  • In open root welding of pipe lines and other delicate electric arc welding operations it has proved beneficial to use a proprietary arc welding process having an arc condition and a short circuit condition in each of a plurality of low frequency welding cycles, such as less than about 200 cycles per second. The power supplied to the welding electrode in such process is controlled according to a detected short circuit and the anticipation of the metal breaking during the short circuit condition. This short circuit welding process accurately controls heat and drastically reduces spatter. It is referred to in the welding industry as the proprietary STT welding process of The Lincoln Electric Company and is performed by a welder having a power source wherein an output power switch is open at initiation of the short circuit condition and opened to subsequently initiate the arc condition after a short circuit. Such welder is normally manufactured with a maximum capacity of approximately 300-500 amperes. Consequently, the welder has a limited deposition rate. There is a need for a welding system to perform the proprietary welding process, but having a substantially greater maximum current rating. Heretofore, this increased current capacity was obtainable only by designing a special power source and output switch machine. The switch had to have a drastically higher current capacity and the remainder of the power source had to have a substantially greater current generating capacity. These requirements substantially increased the cost, which cost was not justified due to substantially less applications. The concept of paralleling power sources was not practical because each of the power sources would produce its own waveform, which resulted in an unacceptable welding result. Thus, there is a need for an inexpensive welding system to perform the proprietary welding process using a short circuit condition and an arc condition with a current capacity substantially greater than 300-500 amperes.
  • THE INVENTION
  • The invention involves an electric arc welding system for performing an arc welding process having an arc condition and a short circuit condition in successive welding cycles. The power supplied to a welding electrode is controlled according to a detected short circuit and an anticipated metal breaking fuse condition. In this process, a controlled boost pulse is provided during the arc condition to establish an arc length and to form molten metal. The boost pulse is followed by a controlled current to form the molten metal ball on the end of an advancing electrode so that the ball is subsequently transferred by surface tension. During the surface transfer, the molten metal of the ball necks down and is separated by a “fuse” accelerated through an electromagnetic pinch action. At the start of the metal transfer and at the end of the metal transfer an output power switch in the welder reduces the arc current to control the transfer action and reduce spatter. This type of welding system has in the past been limited to about 300-500 amperes. In accordance with the present invention, the system can perform the described short circuit welding process with a current capacity exceeding 600 amperes. Indeed, the welding current capability can be well over 800-1000 amperes. The increased current capacity does not decrease the efficiency of the metal transfer, nor does it increase the spatter when the metal transfer is finalized by the necking action that separates the molten metal ball from the electrode.
  • In accordance with the present invention, the electric arc welding system includes a power lead for providing welding circuit between an advancing welding wire and a workpiece. A short circuit sensor creates a short circuit output signal when the electrode is shorted to the workpiece. There is also a premonition having a “fuse” output signal when a short circuit is about to end to shift between the short circuit condition and the arc condition. This welding system is improved by including at least two power source modules each with a common isolated DC input and an output connected to the power lead of the system. Each of these modules is controlled to perform the short welding process as described. To coordinate the operation of each module, each module comprises a regulated DC to DC converter having a DC output signal with a waveform controlled by a waveform signal from a controller and a power output switch that receives the DC output signal from the power source and is in series with the output power lead. The output switch of each module is opened by a gate signal to the module to reduce the welding current in the power lead. A common controller is used for all modules. The controller is either digital or analog and has a first input for the short circuit output signal and a second input for the fuse output signal. The common controller generates an output for creating the gate signal to reduce the welding current upon the receipt of a signal in either of the first or second inputs to the controller. A circuit uses the inputs to reduce the current for a set short time after a short is detected. Then the circuit reduces the current for a set time when the short circuit is about to break. This gate signal from the control circuit of the controller is directed to each of the modules at the same time to initiate the metal transfer short circuit condition and to terminate the transfer condition. The termination of the transfer is followed by the arc condition having an initial power boost current. Thus, the actual welding process is performed by a plurality of modules that are coordinated by actual sensing of the welding process and creating signals common to all modules. Thus, the modules operate in unison so the 300-500 ampere limitation of each of the modules is multiplied by the number of modules in the system. In this manner, the welding process is performed with the current from a plurality of modules between two and any number. Each module receives signals that control the operation of the modules in unison.
  • In accordance with another aspect of the present invention, the waveform signal is created by a waveform generator having a state table with a given waveform during both the arc condition and the short circuit condition of the welding process. The premonition sensor is a dv/dt detector with a threshold value to create the “fuse” output signal that is used in unison by all of the power supply modules. In practice, the waveform signal is formed by a pulse width modulator. The preferred waveform during the metal transfer operation involves a varied rate of current increase. Indeed, in practice one rate is used at the start of the transfer. Then a second rate is outputted by the waveform.
  • In accordance with the preferred embodiment of the present invention, the regulated converter of each module is a chopper and the input to the modules is a DC signal created by an unregulated, isolated DC converter. In the past, the output stage of the power source for the welder is driven by a regulated input stage. In such system, the output stage is regulated by the parameters of the welding process. Thus, in the past, both stages are regulated. In accordance with the preferred embodiment of this invention, the output stage is regulated and the input to the output stage is not regulated. Of course, such an arrangement would include a further upstream preregulator which concept is not part of the present invention.
  • Still a further aspect of the present invention, there is provided a method for electric are welding. This method comprises providing a plurality of power source modules each generating an essentially identical waveform controlled by a common waveform signal from a controller, connecting the modules between a DC input to provide an output to a single welding operation including an electrode and workpiece, sensing a short circuit between the electrode and workpiece to create a short circuit signal and starting the identical waveform of each module upon creation of the short circuit signal. In practice there is a set time delay after a detected short circuit. This method is used to perform a welding process that requires an output switch that is opened upon creation of the short circuit signal. Furthermore, in the preferred embodiment the input signal is from an unregulated isolated DC to DC converter.
  • The primary object of the present invention is the provision of a welding system to perform a welding process having an arc condition and a short circuit condition where the power supply to a welding electrode is controlled according to a detected short circuit and an anticipated breaking fuse condition. This system utilizes a plurality of modules so that the output current capacity can be increased merely by adding standardized low current modules. These standardized modules are rated to perform the normal low current method.
  • A further object of the present invention is the provision of a welding system as defined above, which welding system coordinates several individual power source modules by common signals from a single controller operated in accordance with real time parameters of the welding process.
  • These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings.
  • BRIEF DESCRIPTION OF DRAWINGS
  • FIG. 1 is a schematic wiring diagram of the preferred embodiment of the present invention;
  • FIG. 1A is a partial analog diagram of the short circuit detecting network used in the embodiment of the invention illustrated in FIG. 1; and,
  • FIG. 2 is a partial wiring diagram illustrating a further feature of the present invention.
  • PREFERRED EMBODIMENT
  • The present invention is directed to welding system A for performing a welding process having an arc condition and a short circuit condition in each of a plurality of low frequency welding cycles, generally less than 200 cps. In this welding process, the power supplied to a welding electrode is controlled according to a detected short circuit and an anticipated metal breaking fuse condition. A controlled boost pulse is provided during the arc condition to establish an arc length and to form a molten metal ball, with the boost pulse being followed by a controlled background current to create a ball that is transferred to the workpiece by a surface tension phenomenon. Such process is well known in the welding industry and is described in several patents owned by The Lincoln Electric Company of Cleveland, Ohio. A few of such patents are Parks U.S. Pat. No. 4,717,807; Parks U.S. Pat. No. 5,003,154; Stava U.S. Pat. No. 5,148,001; Stava U.S. Pat. No. 6,160,241; and, Stava U.S. Pat. No. 6,501,049. As described in FIG. 1, system A includes power source P with input DC signal leads 10, 12. In the preferred embodiment of the invention, the DC signal on these leads is provided by an unregulated DC to DC converter 20 which receives a regulated input on leads 22, 24 from a preregulator. A preregulator normally is a power factor correcting buck converter. Other sources of the DC signal on leads 10, 12 are used when practicing the short circuit welding process to which the present invention is directed. Power source P has an output power lead 30 and a common return or ground lead 32. In practicing the invention, power source P performs the aforementioned welding process at a standard welding station B wherein electrode E, in the form of an advancing wire 40 from supply reel 42, is moved toward workpiece WP. Thus, the welding process is performed between the end of electrode E and workpiece WP. In accordance with standard architecture, an arc current sensor 50, normally in the form of a shunt, is provided to create a voltage signal representing the arc current of the welding process. When performing the welding process to which the invention is directed, a short circuit detector 60, best shown in FIG. 1A, is controlled by the voltage across sensed leads 62, 64. Detector 60 provides a signal on output 66 when the voltage between electrode E and workpiece WP is below a threshold value, indicating a short circuit condition in the welding process. Single controller C causes power source P to perform the desired welding process. Such controller is illustrated schematically as analog components; however, in practice the controller functions are digital and performed by a microprocessor or other digital signal processor. Controller C includes a wave shaper 70 to generate a wave shape W at power lead 30 in accordance with a waveform or wave shape output signal on line 76. The signal shape is from a look up table or other source of desired waveforms or waveform portions. The signal on line 76 can be trimmed in accordance with standard practice by a potentiometer 72 with an arm 74 to define a set point for the waveform generator or wave shaper 70. The voltage on arm 74 is generally related to the magnitude of the arc current being used in the welding process. An output waveform signal for controlling the shape of the waveform or waveform portions during the welding process is directed by line 76 to amplifier 80 having feedback network 82 and a second input 84. Consequently, the signal on output 86 forces the current at lead 30 to track the desired wave shape W set in wave shaper 70. This is standard technology in the welding industry to perform the welding process to which the invention is particularly adapted. The signal on line 86 controls pulse width modulator 100 so the pulses on output line 110 has a frequency of greater than about 20 kHz as determined by oscillator 102 for driving pulse width modulator 100 through the high frequency signal on line 104. Thus, the output pulses on line 110 cause the arc current to track the wave shape W in accordance with standard practice, which may be different for the short circuit condition and the arc condition. To determine when the molten metal ball is ready to and detach from electrode E after there has been a short circuit, premonition circuit 90 monitors the voltage across leads 62, 64. Circuit 90 provides an output signal on line 92 when dv/dt of the welding process reaches a predetermined threshold level indicating an imminent break or “fuse” of the short circuit transferred molten metal.
  • In accordance with standard practice, controller C provides a signal in line 78 when there is a signal in line 66 indicating a short circuit and when there is a subsequent signal in line 92 to indicate that the short circuit is ready to break. Circuit 120 reads the information on line 78 and its sequencing to create a signal in line 122 when the power switch of power supply P is to be opened for a drastic reduction in current based upon the signals from circuit 60 and 90. Circuit 120 produces a signal in line 122 for operating the power switch of power source P to produce the desired welding process. To detect the actual short circuit condition at the start of the short circuit portion of the cycle, the signal on line 78 is created by the signal on line 66. The signal stays on during a short. An analog representation of detector 60 is illustrated in FIG. 1A wherein the arc voltage is sensed by detector 130 having an output lead 132 to direct a voltage representative of the arc voltage to one input of comparator 140. The other input 142 is the reference signal representative of a reference voltage, such as about 6.0 volts DC. Thus, when the voltage across the welding station is decreased below a value such as 6.0 volts DC, a signal is generated in line 66. This initiates the short circuit portion of waveform W. The end of the short circuit condition is sensed by a signal in line 90 to again actuate a signal on output lead 122. The signal on line 92 after a signal on line 66 decreases the arc current rapidly by again opening the power switch of power source P. Thus, a signal on line 122 occurs when there is a short and thereafter when there is an impending break of the short. This is standard technology in the arc welding industry.
  • Power supply P includes power lead 30 and return or ground lead 32 and a waveform signal on line 110. A signal to reduce the arc current in accordance with the process being performed is directed to power source P by line 122. In accordance with the invention, power source P includes a plurality of identical modules P1, P2 and PN. The number of identical modules can vary; however, they are not synchronized in timing but are operated in unison based upon the signals on lines 110, 122. The waveform profiles are controlled by the signal on line 110 and are implemented by the signal on line 122. Consequently, all power modules perform the same waveform or waveform portions and the same reduction of current upon occurrence of a short circuit and upon occurrence of the end of the short circuit portion of the cycle. Each module is identical; therefore, module P1 will be described in detail. This description applies equally to the other modules. Module P1 includes a power source 200, shown as a down chopper or buck converter, having a ground lead 202 and a waveform profile signal from line 204 connected to output line 110 of pulse width modulator 100. Freewheeling diode 206 is connected with ground lead 202 and ultimately to the common return or ground lead 32. Power source 200 includes a DC input signal on lines 210, 212 and an output DC signal on line 214. Chopper or power source 200 drives a switching network through choke 220, which switching network controls current on line 30 and includes a power switch 230 in the form of a Darlington switch operated in accordance with the logic on gate 232 from line 122 of circuit 120. Switch 230 has a parallel snubber circuit 240 including diode 242 and resistor 244 in series with output lead 250 connected directly to power lead 30. Capacitor 246 is connected in parallel with resistor 244 for controlling the voltage across resistor 244 in accordance with standard practice. The power source for performing the welding process to which the present invention is directed includes a single circuit as described in connection with module P1. In practice, this type of power source has an output current capacity of generally 300-500 amperes. Consequently, the welding process was limited to lower currents. In accordance with the invention, one or more additional modules are connected in parallel to operate in unison with power source P1 to increase the current capacity by multiples of the existing current capacity. Thus, by using a standard module with shared leads and control signals, system A can have drastically increased current capacities without requiring a specifically designed power source for diverse high current applications. In this manner, current available to drive the welding process between electrode E and workpiece WP can be increased without designing a high current power source. Such specially designed high current sources have not been added to the product line of electric arc welder manufacturers because of the low volume demand compared to the increased development and inventory costs. Thus, the present invention allows the implementation of the preferred welding process with substantially higher maximum current capabilities without increasing the cost of already designed power sources. In practice, more than two identical power sources are used; however, in accordance with the present invention system A could employ only two power sources P1 and P2.
  • As so far described, the invention relates to a DC waveform with a short circuit section and an arc section. However, an AC implementation can be made, as illustrated in FIG. 2. The power lead 30 and return lead 32 are connected to a polarity switch 250 so a polarity signal on line 252 created by controller C reverses the polarity of one section of the waveform, both sections of the waveform or the whole waveform. Indeed, a small portion of one section of the waveform can be performed at an opposite polarity than the remainder of the section and the remainder of the other section. The waveform is created on output lines 260, 262 connected to the welding operation disclosed in FIG. 1. The polarity is reversed at selected times determined by the logic on line 252.

Claims (99)

1. An electric arc welding system including a power lead for providing welding current between an advancing welding wire and a workpiece, a short circuit sensor having a short circuit output signal when said electrode is shorted with said workpiece, a premonition sensor having a fuse output signal when a short circuit is about to break, said welding system having at least two power source modules each with a common isolated DC input and an output connected to said power lead, each of said modules controlled to perform a short circuit arc welding process having an arc condition and a short circuit condition in each of a plurality of welding cycles, where power supplied to a welding electrode is controlled according to a detected short-circuit and an anticipated metal breaking fuse condition, each of said modules comprising a regulated DC to DC converter having a DC output signal with a waveform controlled by a waveform signal from a controller and an output switch receiving said DC output signal and in series with said power lead, said output switch being opened by a gate signal to reduce said welding current in said power lead, said controller having a first input comprising said short circuit output signal and a second input comprising said fuse output signal and a switch control output for creating said gate signal to reduce said welding current upon initial receipt of a signal on either of said first or second inputs to said controller.
2. An electric arc welding system as defined in claim 1 wherein said waveform signal is created by a waveform generator loaded with a given waveform during both said arc condition and said short circuit condition.
3. An electric arc system as defined in claim 1 wherein said premonition sensor is a dv/dt detector with a threshold value to create said fuse output signal.
4. An electric arc welding system as defined in claim 3 wherein said waveform signal is from a pulse width modulator.
5. An electric arc welding system as defined in claim 2 wherein said waveform signal is from a pulse width modulator.
6. An electric arc welding system as defined in claim 1 wherein said waveform signal is from a pulse width modulator.
7. An electric arc welding system as defined in claim 6 wherein said regulated DC to DC converter is a chopper.
8. An electric arc welding system as defined in claim 5 wherein said regulated DC to DC converter is a chopper.
9. An electric arc welding system as defined in claim 4 wherein said regulated DC to DC converter is a chopper.
10. An electric arc welding system as defined in claim 3 wherein said regulated DC to DC converter is a chopper.
11. An electric arc welding system as defined in claim 2 wherein said regulated DC to DC converter is a chopper.
12. An electric arc welding system as defined in claim 1 wherein said regulated DC to DC converter is a chopper.
13. An electric arc welding system as defined in claim 12 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
14. An electric arc welding system as defined in claim 11 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
15. An electric arc welding system as defined in claim 10 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
16. An electric arc welding system as defined in claim 9 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
17. An electric arc welding system as defined in claim 8 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
18. An electric arc welding system as defined in claim 7 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
19. An electric arc welding system as defined in claim 6 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
20. An electric arc welding system as defined in claim 5 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
21. An electric arc welding system as defined in claim 4 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
22. An electric arc welding system as defined in claim 3 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
23. An electric arc welding system as defined in claim 2 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
24. An electric arc welding system as defined in claim 1 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
25. An electric arc welding system as defined in claim 24 wherein said system includes more than two modules.
26. An electric arc welding system as defined in claim 12 wherein said system includes more than two modules.
27. An electric arc welding system as defined in claim 6 wherein said system includes more than two modules.
28. An electric arc welding system as defined in claim 3 wherein said system includes more than two modules.
29. An electric arc welding system as defined in claim 2 wherein said system includes more than two modules.
30. An electric arc welding system as defined in claim 1 wherein said system includes more than two modules.
31. An electric arc welding system as defined in claim 30 wherein said controller includes a circuit to hold said welding current reduced for a set time after said first input to said controller.
32. An electric arc welding system as defined in claim 30 wherein said controller includes a circuit to hold said welding current reduced for a set time after said second input to said controller.
33. An electric arc welding system as defined in claim 30 wherein said waveform during said short circuit portion has a controlled rate of rise of said welding current.
34. An electric arc welding system as defined in claim 33 wherein said rate of rise is varied.
35. An electric arc welding system as defined in claim 24 wherein said controller includes a circuit to hold said welding current reduced for a set time after said first input to said controller.
36. An electric arc welding system as defined in claim 24 wherein said controller includes a circuit to hold said welding current reduced for a set time after said second input to said controller.
37. An electric arc welding system as defined in claim 24 wherein said waveform during said short circuit portion has a controlled rate of rise of said welding current.
38. An electric arc welding system as defined in claim 37 wherein said rate of rise is varied.
39. An electric arc welding system as defined in claim 12 wherein said controller includes a circuit to hold said welding current reduced for a set time after said first input to said controller.
40. An electric arc welding system as defined in claim 12 wherein said controller includes a circuit to hold said welding current reduced for a set time after said second input to said controller.
33. An electric arc welding system as defined in claim 12 wherein said waveform during said short circuit portion has a controlled rate of rise of said welding current.
42. An electric arc welding system as defined in claim 41 wherein said rate of rise is varied.
43. An electric arc welding system as defined in claim 6 wherein said controller includes a circuit to hold said welding current reduced for a set time after said first input to said controller.
44. An electric arc welding system as defined in claim 6 wherein said controller includes a circuit to hold said welding current reduced for a set time after said second input to said controller.
45. An electric arc welding system as defined in claim 6 wherein said waveform during said short circuit portion has a controlled rate of rise of said welding current.
46. An electric arc welding system as defined in claim 45 wherein said rate of rise is varied.
47. An electric arc welding system as defined in claim 1 wherein said controller includes a circuit to hold said welding current reduced for a set time after said first input to said controller.
48. An electric arc welding system as defined in claim 1 wherein said controller includes a circuit to hold said welding current reduced for a set time after said second input to said controller.
49. An electric arc welding system as defined in claim 1 wherein said waveform during said short circuit portion has a controlled rate of rise of said welding current.
50. An electric arc welding system as defined in claim 49 wherein said rate of rise is varied.
51. An electric arc welder as defined in claim 48 including a polarity switch to reverse the polarity of welding current at selected times.
52. An electric arc welder as defined in claim 47 including a polarity switch to reverse the polarity of welding current at selected times.
53. An electric arc welder as defined in claim 30 including a polarity switch to reverse the polarity of welding current at selected times.
54. An electric arc welder as defined in claim 24 including a polarity switch to reverse the polarity of welding current at selected times.
55. An electric arc welder as defined in claim 12 including a polarity switch to reverse the polarity of welding current at selected times.
56. An electric arc welder as defined in claim 6 including a polarity switch to reverse the polarity of welding current at selected times.
57. An electric arc welder as defined in claim 3 including a polarity switch to reverse the polarity of welding current at selected times.
58. An electric arc welder as defined in claim 2 including a polarity switch to reverse the polarity of welding current at selected times.
59. An electric arc welder as defined in claim 1 including a polarity switch to reverse the polarity of welding current at selected times.
60. A power source module comprising a DC input for said module connected to a regulated DC to DC converter having a DC output signal with a waveform controlled by a waveform signal on a first controller input and an output switch receiving said DC output signal and a DC output for said module, said output switch being opened by a gate signal on a second controller input to reduce the current on said DC output of said module.
61. A power source module as defined in claim 60 wherein said regulated DC to DC converter is a chopper.
62. A power source as defined in claim 61 wherein said DC output signal of said regulated DC to DC converter is connected to said output switch by a chopper.
63. A power source as defined in claim 60 wherein said DC output signal of said regulated DC to DC converter is connected to said output switch by a chopper.
64. A power source module as defined in claim 63 including a free wheeling diode between said converter and said choke.
65. A power source module as defined in claim 62 including a free wheeling diode between said converter and said choke.
66. A power module as defined in claim 65 wherein said waveform signal is a series of pulses from a pulse width modulator.
67. A power source as defined in claim 66 wherein said pulse width modulator is controlled by a waveform generator.
68. A power module as defined in claim 64 wherein said waveform signal is a series of pulses from a pulse width modulator.
69. A power source as defined in claim 68 wherein said pulse width modulator is controlled by a waveform generator.
70. A power module as defined in claim 63 wherein said waveform signal is a series of pulses from a pulse width modulator.
71. A power source as defined in claim 70 wherein said pulse width modulator is controlled by a waveform generator.
72. A power module as defined in claim 62 wherein said waveform signal is a series of pulses from a pulse width modulator.
73. A power source as defined in claim 72 wherein said pulse width modulator is controlled by a waveform generator.
74. A power module as defined in claim 61 wherein said waveform signal is a series of pulses from a pulse width modulator.
75. A power source as defined in claim 74 wherein said pulse width modulator is controlled by a waveform generator.
76. A power module as defined in claim 60 wherein said waveform signal is a series of pulses from a pulse width modulator.
77. A power source as defined in claim 76 wherein said pulse width modulator is controlled by a waveform generator.
78. A method for electric arc welding comprising:
(a) providing a plurality of power source modules each generating an essentially identical waveform controlled by a common waveform signal from a controller;
(b) connecting said modules between a DC input to provide an output to a single welding operation including an electrode and workpiece;
(c) sensing a short circuit between said electrode and said workpiece to create a short circuit signal; and,
(d) modifying said identical waveform of each module upon creation of said short circuit signal.
79. A method as defined in claim 78 wherein said essentially identical waveform has an arc condition and a short circuit condition.
80. A method as defined in claim 79 wherein each module has an output switch opened upon creation of said short circuit signal.
81. A method as defined in claim 78 wherein each module has an output switch opened upon creation of said short circuit signal.
82. A method as defined in claim 81 further including:
(e) providing said DC input from an unregulated isolation DC to DC converter.
83. A method as defined in claim 80 further including:
(e) providing said DC input from an unregulated isolation DC to DC converter.
84. A method as defined in claim 79 further including:
(e) providing said DC input from an unregulated isolation DC to DC converter.
85. A method as defined in claim 78 further including:
(e) providing said DC input from an unregulated isolation DC to DC converter.
86. A method for electric arc welding comprising:
(a) providing a plurality of power source modules each generating an essentially identical waveform controlled by a common waveform signal from a controller;
(b) connecting said modules between a DC input to provide an output current to a single welding operation including an electrode and workpiece;
(c) sensing a condition between said electrode and said workpiece to create a condition signal; and,
(d) modifying said identical waveform of each module upon creation of said condition signal.
87. A method as defined in claim 86 wherein said module has an output switch opened upon creation of said condition signal.
88. A method as defined in claim 87 further including:
(e) providing said DC input from an unregulated isolation DC to DC converter.
89. A method as defined in claim 86 further including:
(e) providing said DC input from an unregulated isolation DC to DC converter.
90. A method as defined in claim 89 including:
(f) changing the polarity of said output current at selected times.
91. A method as defined in claim 88 including:
(f) changing the polarity of said output current at selected times.
92. An electric arc welding system including a powder lead for providing welding current between an advancing welding wire and a workpiece, said welding system having at least two power source modules each with a common isolated DC input and an output connected to said power lead, each of said modules comprising a regulated DC to DC converter having a DC output signal with a waveform controlled by a waveform signal from a controller and in series with said power lead wherein said waveform signal is created by a waveform generator loaded with a given waveform.
93. An electric arc welding system as defined in claim 92 wherein said waveform signal is from a pulse width modulator.
94. An electric rc welding system as defined in claim 92 wherein said regulated DC to DC converter is a chopper.
95. An electric arc welding system as defined in claim 92 wherein said isolated DC input signal is created by an unregulated, isolation DC to DC converter.
96. An electric arc welding system as defined in claim 92 wherein said system includes more than two modules.
97. An electric arc welder as defined in claim 92 including a polarity switch to reverse the polarity of welding current at selected times.
98. An electric arc welding system including a power lead for providing welding current between an advancing welding wire and a workpiece, said welding system having at least two power source modules each with a common DC input and an output connected to said power lead, each of said modules comprising a regulated DC to DC converter having a DC output signal with a waveform controlled by a waveform signal from a controller and in series with said power lead wherein said waveform signal is created by a waveform generator loaded with a given waveform and a circuit to change the polarity of said welding current at selected times.
99. An electric arc welding system as defined in claim 98 wherein said waveform signal is from a pulse width modulator.
US11/090,576 2005-03-28 2005-03-28 Arc welding system Active 2028-10-13 US7968822B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/090,576 US7968822B2 (en) 2005-03-28 2005-03-28 Arc welding system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US11/090,576 US7968822B2 (en) 2005-03-28 2005-03-28 Arc welding system

Publications (2)

Publication Number Publication Date
US20060213891A1 true US20060213891A1 (en) 2006-09-28
US7968822B2 US7968822B2 (en) 2011-06-28

Family

ID=37034159

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/090,576 Active 2028-10-13 US7968822B2 (en) 2005-03-28 2005-03-28 Arc welding system

Country Status (1)

Country Link
US (1) US7968822B2 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070215585A1 (en) * 2006-03-15 2007-09-20 Lincoln Global, Inc. High current AC welder
US20070246448A1 (en) * 2006-04-20 2007-10-25 Daihen Corporation Polarity switching method in consumable electrode AC pulse arc welding
US20110309054A1 (en) * 2010-06-17 2011-12-22 Illinois Tool Works Inc. Modular direct current power source
US20130264323A1 (en) * 2012-04-05 2013-10-10 Lincoln Global, Inc. Process for surface tension transfer short ciruit welding
CN103418892A (en) * 2013-07-18 2013-12-04 北京工业大学 Welding source device with energy keeping loop and control method
CN103692058A (en) * 2013-12-31 2014-04-02 上海广为焊接设备有限公司 Soft start circuit with power correction circuit inverter-type welding machine
CN103746549A (en) * 2013-12-23 2014-04-23 上海广为焊接设备有限公司 Improving apparatus and method for EMC of high-power single-phase inverter welding machine and welding machine
CN104965536A (en) * 2015-06-24 2015-10-07 上海沪工焊接集团股份有限公司 Temperature control circuit and temperature control method
CN105720841A (en) * 2014-12-02 2016-06-29 辽宁汉昌高新科技有限公司 Self-excitation flyback switching power supply with soft switching circuit
US10543553B2 (en) * 2017-03-07 2020-01-28 Lincoln Global, Inc. High current AC welder

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102218582B (en) * 2010-04-16 2014-01-29 深圳市佳士科技股份有限公司 Submerged arc welding current pulse control circuit
CN103769721B (en) * 2014-01-27 2015-08-05 深圳市佳士科技股份有限公司 The accurate short circuiting transfer control circuit of arc welding based on AVR single chip

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4717807A (en) * 1986-12-11 1988-01-05 The Lincoln Electric Company Method and device for controlling a short circuiting type welding system
US5003154A (en) * 1986-12-11 1991-03-26 The Lincoln Electric Company Apparatus and method of short circuiting arc welding
US5148001A (en) * 1986-12-11 1992-09-15 The Lincoln Electric Company System and method of short circuiting arc welding
US5406051A (en) * 1993-04-29 1995-04-11 Electric Power Research Institute Welding machine with a high frequency converter
US5786992A (en) * 1994-04-08 1998-07-28 Vlt Corporation Efficient power conversion
US6160241A (en) * 1999-03-16 2000-12-12 Lincoln Global, Inc. Method and apparatus for electric arc welding
US6215100B1 (en) * 1998-01-09 2001-04-10 Lincoln Global, Inc. Short circuit welder
US6291798B1 (en) * 1999-09-27 2001-09-18 Lincoln Global, Inc. Electric ARC welder with a plurality of power supplies
US6343026B1 (en) * 2000-11-09 2002-01-29 Artesyn Technologies, Inc. Current limit circuit for interleaved converters
US6365874B1 (en) * 2000-05-22 2002-04-02 Lincoln Global, Inc. Power supply for electric arc welding
US6441342B1 (en) * 2000-11-20 2002-08-27 Lincoln Global, Inc. Monitor for electric arc welder
US6472634B1 (en) * 2001-04-17 2002-10-29 Lincoln Global, Inc. Electric arc welding system
US6501049B2 (en) * 2001-01-23 2002-12-31 Lincoln Global, Inc. Short circuit arc welder and method of controlling same
US6504132B1 (en) * 2000-09-05 2003-01-07 Lincoln Global, Inc. Electric arc welder for variable AC input
US6749008B2 (en) * 2002-04-11 2004-06-15 Denso Corporation Vehicle air-conditioning system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6847008B2 (en) 2003-01-17 2005-01-25 Lincoln Global, Inc. Electric arc welding system

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5003154A (en) * 1986-12-11 1991-03-26 The Lincoln Electric Company Apparatus and method of short circuiting arc welding
US5148001A (en) * 1986-12-11 1992-09-15 The Lincoln Electric Company System and method of short circuiting arc welding
US4717807A (en) * 1986-12-11 1988-01-05 The Lincoln Electric Company Method and device for controlling a short circuiting type welding system
US5406051A (en) * 1993-04-29 1995-04-11 Electric Power Research Institute Welding machine with a high frequency converter
US5786992A (en) * 1994-04-08 1998-07-28 Vlt Corporation Efficient power conversion
US6215100B1 (en) * 1998-01-09 2001-04-10 Lincoln Global, Inc. Short circuit welder
US6160241A (en) * 1999-03-16 2000-12-12 Lincoln Global, Inc. Method and apparatus for electric arc welding
US6291798B1 (en) * 1999-09-27 2001-09-18 Lincoln Global, Inc. Electric ARC welder with a plurality of power supplies
US6365874B1 (en) * 2000-05-22 2002-04-02 Lincoln Global, Inc. Power supply for electric arc welding
US6600134B2 (en) * 2000-05-22 2003-07-29 Lincoln Global, Inc. Power supply for electric arc welding
US6504132B1 (en) * 2000-09-05 2003-01-07 Lincoln Global, Inc. Electric arc welder for variable AC input
US6343026B1 (en) * 2000-11-09 2002-01-29 Artesyn Technologies, Inc. Current limit circuit for interleaved converters
US6441342B1 (en) * 2000-11-20 2002-08-27 Lincoln Global, Inc. Monitor for electric arc welder
US6501049B2 (en) * 2001-01-23 2002-12-31 Lincoln Global, Inc. Short circuit arc welder and method of controlling same
US6472634B1 (en) * 2001-04-17 2002-10-29 Lincoln Global, Inc. Electric arc welding system
US6749008B2 (en) * 2002-04-11 2004-06-15 Denso Corporation Vehicle air-conditioning system

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9592566B2 (en) 2004-04-01 2017-03-14 Lincoln Global, Inc. High current AC welder
US20170173721A1 (en) * 2004-04-01 2017-06-22 Lincoln Global, Inc. High current ac welder
US20070215585A1 (en) * 2006-03-15 2007-09-20 Lincoln Global, Inc. High current AC welder
US8592720B2 (en) * 2006-04-20 2013-11-26 Daihen Corporation Polarity switching method in consumable electrode AC pulse arc welding
US20070246448A1 (en) * 2006-04-20 2007-10-25 Daihen Corporation Polarity switching method in consumable electrode AC pulse arc welding
US20110309054A1 (en) * 2010-06-17 2011-12-22 Illinois Tool Works Inc. Modular direct current power source
US9156103B2 (en) * 2010-06-17 2015-10-13 Illinois Tool Works Inc. Modular direct current power source
US20130264323A1 (en) * 2012-04-05 2013-10-10 Lincoln Global, Inc. Process for surface tension transfer short ciruit welding
WO2013150366A1 (en) * 2012-04-05 2013-10-10 Lincoln Global, Inc. Improved process for surface tension transfer short circuit welding
CN103418892A (en) * 2013-07-18 2013-12-04 北京工业大学 Welding source device with energy keeping loop and control method
CN103746549A (en) * 2013-12-23 2014-04-23 上海广为焊接设备有限公司 Improving apparatus and method for EMC of high-power single-phase inverter welding machine and welding machine
CN103692058A (en) * 2013-12-31 2014-04-02 上海广为焊接设备有限公司 Soft start circuit with power correction circuit inverter-type welding machine
CN105720841A (en) * 2014-12-02 2016-06-29 辽宁汉昌高新科技有限公司 Self-excitation flyback switching power supply with soft switching circuit
CN104965536A (en) * 2015-06-24 2015-10-07 上海沪工焊接集团股份有限公司 Temperature control circuit and temperature control method
US10543553B2 (en) * 2017-03-07 2020-01-28 Lincoln Global, Inc. High current AC welder

Also Published As

Publication number Publication date
US7968822B2 (en) 2011-06-28

Similar Documents

Publication Publication Date Title
CN1186160C (en) Series connected electrode type welding machine and welding method using two electrodes
KR100815659B1 (en) Modular power source for electric arc welding and output chopper
JP4303714B2 (en) Electric arc welding power supply
AU729425B2 (en) High current welding power supply
KR900003877B1 (en) Method and device for controlling welding power supply to avoid sputtering of the weld material
CN1247357C (en) Arc welding machine with multi-power supply
CN1203953C (en) Short-circuit arc welding machine and method for controlling thereof
US6093906A (en) Method of pipe welding
AU2005202559B2 (en) Power source for electric arc welding
EP1886756B1 (en) Pulse arc welding control method and pulse arc welding device
US6515259B1 (en) Electric arc welder using high frequency pulses
US8963045B2 (en) Non-linear adaptive control system and method for welding
US4972064A (en) Apparatus for short circuiting arc welding
EP2205392B1 (en) Method and device to build-up, clad, or hard-face with minimal admixture
US20060207983A1 (en) Pipe seam tack welding methods and apparatus using modified series arc welding
AU2004212533B2 (en) Short circuit arc welder and method of controlling same
EP1439021B1 (en) Electric arc welding system
JP3206714B2 (en) Pulse arc welding method and apparatus
KR100490241B1 (en) System and method for controlling an electric arc welder
CN1289249C (en) Power supply of short-circuit arc-welding and automatic soldering machine using the power supply
JP4234105B2 (en) Electric arc pulse welder with short circuit control
US7166817B2 (en) Electric ARC welder system with waveform profile control for cored electrodes
CN1830611A (en) Welding current controlling method in arc welding process using consumable electrode upon detection of constriction
JP2000288730A (en) Electric arc welding method and apparatus thereof
EP1543909B1 (en) AC electric arc welding system and process with two electrodes

Legal Events

Date Code Title Description
AS Assignment

Owner name: LINCOLN GLOBAL, INC., CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:STAVA, ELLIOTT K.;REEL/FRAME:016433/0554

Effective date: 20050318

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 8